CN110727162B

CN110727162B - Projection type image display device

Info

Publication number: CN110727162B
Application number: CN201910992486.4A
Authority: CN
Inventors: 石岛英纪; 乾真朗; 大岛浩; 松井信树
Original assignee: Maxell Ltd
Current assignee: Maxell Ltd
Priority date: 2015-05-19
Filing date: 2015-05-19
Publication date: 2021-06-22
Anticipated expiration: 2035-05-19
Also published as: CN110703547B; US10642137B2; CN110727162A; JPWO2016185550A1; CN107615164A; CN110703547A; CN110703548A; CN107615164B; US20180143520A1; WO2016185550A1; JP6392454B2; CN110703548B

Abstract

A lens moving mechanism (32) of a projection type image display device (10) of the present invention comprises: a horizontally movable base (60) for moving the projection lens (31) in the horizontal direction and a vertically movable base (70) for moving the projection lens in the vertical direction; and a horizontal driving actuator (61) and a vertical driving actuator (71) for driving them. The driving forces from the horizontal driving actuator (61) and the vertical driving actuator (71) are transmitted via a lead screw (671(751)) and 2 lead screw nuts (672, 672b (752, 752b)) engaged therewith, respectively, to move the horizontally movable base and the vertically movable base. A pressing elastic member (672c (752c)) is installed so that 2 lead screw nuts are moved away from or close to each other in the axial direction of the lead screw. With this configuration, backlash in the movement of the lens is reduced and delay in the movement operation is eliminated.

Description

Projection type image display device

Technical Field

The present invention relates to a projection type video display device, and more particularly to a lens moving mechanism for moving a projection lens.

Background

A projection type image display device such as a liquid crystal projector irradiates a display element such as a liquid crystal panel with light emitted from a light source such as a mercury lamp, and projects an image formed by the display element on a screen or the like in an enlarged manner from a projection lens. An optical system of the apparatus includes an optical unit (hereinafter, referred to as an optical engine) that irradiates light emitted from a light source to a liquid crystal panel to form an image, and a projection optical system that projects the image formed by the liquid crystal panel in an enlarged manner by a projection lens.

The projection optical system is provided with a lens moving mechanism for moving the projection lens in a direction perpendicular to the optical axis in order to adjust the image display position on the screen. The lens moving mechanism is a mechanism that moves the projection lens in 2 directions orthogonal to the optical axis of the projection light, i.e., in the horizontal direction and the vertical direction, and improvement of operability is required. Patent document 1 proposes a mechanism that can easily understand the movement direction of the projection optical system by aligning the movement direction of the projection optical system with the direction of the operation knob in order to improve operability.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-62852

Disclosure of Invention

Problems to be solved by the invention

A general lens moving mechanism includes an X slider (X base) for moving a projection lens in a horizontal direction and a driving mechanism thereof; and a Y slider (Y base) for moving the projection lens in the vertical direction and a driving mechanism thereof. In the lens moving mechanism described in patent document 1 and the like, each driving mechanism is constituted by a drive transmission member such as a cam or a gear, but a gap called a backlash is provided in a coupling portion of these drive transmission members, and each slider is allowed to move smoothly. On the other hand, there are problems as follows: when the projection lens reverses the movement direction from left to right and from top to bottom, the X, Y slider does not operate until the gap of the backlash is filled, and the movement operation is delayed and the operability is degraded.

Further, the lens moving mechanism has a function of correcting the tilt of the optical axis of the projection lens, and conventionally, the tilt is corrected by adjusting the lens by a plurality of adjusting bolts. However, when a projection lens is replaced and a heavy lens is attached, the optical axis is inclined by the weight of the lens, and further correction is necessary. The existing method for adjusting by utilizing a plurality of adjusting bolts has the problem of complicated adjusting method.

The invention provides a projection type image display device having a lens moving mechanism which reduces backlash, eliminates delay of moving operation, and easily adjusts inclination of an optical axis.

Means for solving the problems

The present invention is a projection type image display device for projecting an image from a projection lens, including a lens moving mechanism for holding the projection lens and moving the projection lens in 2 axial directions orthogonal to an optical axis of projection light, the lens moving mechanism including: a horizontally movable base for moving the projection lens in the horizontal direction and a vertically movable base for moving the projection lens in the vertical direction; and a horizontal driving actuator for driving the horizontal movable base and a vertical driving actuator for driving the vertical movable base, wherein driving forces from the horizontal driving actuator and the vertical driving actuator are transmitted via the lead screw and 2 lead screw nuts engaged therewith, respectively, to move the horizontal movable base and the vertical movable base, and the 2 lead screw nuts are pressed by the elastic member, so that the 2 lead screw nuts are moved away from or moved close to each other in the axial direction of the lead screw.

Further, an optical axis adjustment guide is inserted from the lens moving mechanism side to the common base holding the lens moving mechanism, the optical axis adjustment guide has a recess near the tip of the bolt portion, a fixing bolt inserted from the common base side is engaged with the recess, and the inclination of the optical axis of the projection lens held by the lens moving mechanism is corrected by adjusting the insertion amount of the optical axis adjustment guide.

Effects of the invention

The present invention can provide a projection type image display device which is easy to adjust the inclination of the optical axis of the lens, has no delay of the lens moving mechanism, and has excellent operability.

Drawings

Fig. 1 is a diagram showing an overall configuration of a projection type image display device 10.

Fig. 2 is a diagram showing the overall configuration of the optical engine 2.

Fig. 3 is a diagram showing the operation of the entire projection optical system 3 and the lens moving mechanism 32.

Fig. 4A is an exploded view of the projection optical system 3.

Fig. 4B is an exploded view of the projection optical system 3.

Fig. 5 is an overall view of the lens moving mechanism 32 and the common base 4.

Fig. 6 is an exploded view of the lens moving mechanism 32 and the common base 4.

Fig. 7 is an overall view of the lens moving mechanism 32.

Fig. 8A is an exploded view of the lens moving mechanism 32.

Fig. 8B is a further exploded view of the Y base 70.

Fig. 9 is an assembly diagram of the lens moving mechanism 32.

Fig. 10 is a diagram showing the horizontal drive mechanism.

Fig. 11 is a diagram showing a vertical driving mechanism.

Fig. 12 is a diagram showing an internal structure of the horizontal driving screw.

Fig. 13 is a diagram showing an internal structure of the vertical drive screw.

Fig. 14 is an explanatory diagram for reducing backlash using a double nut structure.

Fig. 15 is a diagram showing another configuration example of the structure of the double nut.

Fig. 16 is a view showing a specific shape of the auxiliary nut.

Fig. 17 is a sectional view showing an optical axis correction mechanism of the projection lens.

Fig. 18 is a diagram illustrating an example of optical axis correction of the projection lens.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1

Fig. 1 is a diagram showing the entire configuration of a projection type video display device 10, and shows the internal structure of the device except for the casing. The housing 1 houses therein: an optical engine 2 serving as an optical system for emitting light from a light source and irradiating the light onto a liquid crystal panel serving as a display element to form an image; and a projection optical system 3 for enlarging and projecting an image formed on the liquid crystal panel by a projection lens. In addition, a power supply unit, a cooling unit, a video signal circuit, a control circuit, and the like, which are not shown, are housed.

Fig. 2 is a diagram showing the entire configuration of the optical engine 2. The optical engine 2 includes a light source unit 21, a color separation optical system 22, and a color synthesis optical system 23. The light source unit 21 emits substantially white light using a light source such as an ultra-high pressure mercury lamp. The color separation optical system 22 separates substantially white light into three primary colors of RGB light, and guides the three primary colors of RGB light to the corresponding liquid crystal panels. The color combining optical system 23 includes an RGB liquid crystal panel and a cross dichroic prism, forms an image based on RGB signals, and performs color combining of the image. The light source unit 21 may use an LED or a laser light in addition to the silver light, and may use either a transmissive type or a reflective type liquid crystal panel or a DMD (digital mirror device).

Fig. 3 is a diagram showing the entire projection optical system 3 and the operation of the lens moving mechanism 32. The projection optical system 3 is composed of a projection lens 31 and a lens moving mechanism 32, and the lens moving mechanism 32 is held by a common base 4. The optical engine 2 is mounted on the rear side of the common base 4. The image light emitted from the color combining optical system 23 of the optical engine 2 is enlarged by the projection lens 31 and projected onto the screen 5. The lens moving mechanism 32 holds the projection lens 31 and moves the projection lens 31 in 2 axial directions orthogonal to the projection optical axis, that is, in the horizontal direction and the vertical direction. Thereby, the position of the image projected on the screen 5 can be adjusted by moving in the horizontal direction and in the vertical direction.

Fig. 4A and 4B are exploded views of the projection optical system 3, and show an exploded state of the projection lens 31 and the lens moving mechanism 32. As shown in fig. 4A, the lens barrel 311 of the projection lens 31 has a flange (projecting portion) 312, and the projection lens 31 is attached to the lens moving mechanism 32 by fitting the flange 312 to a recess 321 provided in the lens moving mechanism 32. Fig. 4B is a rear view of the projection lens 31, with, for example, 3 flanges 312 around the barrel 311. Similarly, the lens moving mechanism 32 is also provided with recesses 321 at 3 places.

Fig. 5 is an overall view of the lens moving mechanism 32 and the common base 4, and fig. 6 is an exploded view of the lens moving mechanism 32 and the common base 4. In the following description, the optical axis direction of the projection light is referred to as the Z direction, the horizontal direction orthogonal to the above direction is referred to as the X direction, and the vertical direction is referred to as the Y direction.

The common base 4 has a fixed wall 41 standing on the center portion and

pedestal portions

42 and 43 on both sides thereof. The lens moving mechanism 32 is fixed to a fixing wall 41 of a mount 43 mounted on the front. The optical engine 2 is mounted on the rear pedestal portion 42. When the lens moving mechanism 32 is attached to the fixed wall 41, the lens position correction bolts 411a to 411d, the springs 412a to 412d, and the attachment bolt 413 are used. This is to correct the deviation of the lens position in the optical axis direction due to the tolerance of the scratch after the lens moving mechanism is attached, in order to make the distance (back focus) from the liquid crystal panel surface of the optical engine 2 to the rear end of the projection lens proper.

In the assembling operation of the

lens moving mechanism

32, 4 lens position correction bolts 411a to 411d are inserted from the back surface side thereof, 4 mounting bolts 413 are inserted from the front surface side thereof, and the fixing wall 41 is engaged with springs 412a to 412 d. By adjusting the insertion amount of the lens position correction bolts 411a to 411d, the position of the lens moving mechanism 32, that is, the position of the projection lens 31 held by the lens position correction bolts can be adjusted. Further, the lens moving mechanism 32 is supported by the urging forces of the springs 412a to 412d, thereby preventing the lens from falling due to the weight of the projection lens 31.

Fig. 7 is an overall view showing the lens moving mechanism 32. Fig. 8A is an exploded view showing the lens moving mechanism 32. The lens moving mechanism 32 is configured by stacking a fixed base 50 attached to the common base 4, an X-axis movable base 60 (hereinafter, abbreviated as X base) that moves in the X direction, and a Y-axis movable base 70 (hereinafter, abbreviated as Y base) that holds the projection lens 31 and moves it in the Y direction. The X base 60 is moved in the X direction on the fixed base 50 by a horizontal driving actuator 61 (hereinafter, referred to as an X axis actuator) attached to the fixed base 50. The Y base 70 is moved in the Y direction on the X base 60 by a vertical drive actuator 71 (hereinafter, referred to as a Y-axis actuator) attached to the X base. The above-described components are configured such that the X base 60 is sandwiched between the fixed base 50 and the Y base 70.

When driving in the X-axis direction, the positioning pin provided on the X base 60 moves along the positioning pin receiving groove 51 provided on the fixed base 50, thereby driving in the X-axis direction. Similarly, the positioning pin 62 provided on the X base 60 moves along the positioning pin receiving groove provided on the Y base 70, thereby driving in the Y axis direction. Further, since the frictional force can be reduced by the surface sliding of the fixed base 50 and the Y base 70, the members having a small friction coefficient (the movable slide bases 52 and 72) are attached to the fixed base 50 and the Y base 70, and the frictional resistance is reduced by applying a lubricant.

In order to prevent the lubricant applied by the surface sliding from being pushed out of the movable slide bases 52 and 72, grooves for storing the lubricant are provided in the movable slide bases 52 and 72. The fixed base 50 is provided with a potentiometer 53 for detecting the position of the X base 60 and an end point sensor 54 for detecting the end point of movement. Similarly, a potentiometer 63 and an end point sensor 64 for detecting the position of the Y axis 70 are provided on the X base 60.

Fig. 8B is a further exploded view of the Y base 70, and a method of attaching and detaching the projection lens 31 will be described with reference to this drawing. The Y base 70 is divided into a lens pressing ring 701 and a lens pressing holder 702 to hold the projection lens 31. In order to hold the projection lens 31, the Y base 70 is provided with recesses 321(3 places) to be engaged with flanges 312 (see fig. 4B) of the lens barrel 311 provided in the projection lens 31. The depth of the recess 321 is slightly smaller than the width of the flange 312 in the Z direction. The lens retaining ring 701 and the lens retaining holder 702 are provided with notches 322 and 323(3 positions) so that the flange 312 passes through the lens retaining ring 701 and the lens retaining holder 702 when attached and detached.

Further, the lens retaining ring 701 is provided with a handle 324 for switching locking/unlocking of holding the lens. When the projection lens 31 is attached, the lens retaining ring 701 is rotated by the handle 324, the recess 321 is engaged with the notch 322, and the flange 312 is engaged with the recess 321. Then, the handle 324 is turned again, and the projection lens 31 is pressed against the lens pressing ring 701, whereby the projection lens 31 is fixed to the Y base 70. When the projection lens 31 is to be removed, the projection lens 31 can be removed by rotating the lens retaining ring 701 in the reverse direction using the handle 324 and then engaging the concave portion 321 with the notch portion 322 of the lens retaining ring 701.

Fig. 9 is an assembly diagram of the lens moving mechanism 32. In assembly, the X base 60 is sandwiched between the fixed base 50 and the Y base 70 so that the shaft 81 passes through. An engagement bolt 82a is attached to the shaft 81 on the side of the fixed base 50 via a pressing spring 80, and an engagement bolt 82b is inserted from the shaft 81 on the side of the Y base 70. The fixing base 50, the X base 60, and the Y base 70 are pressed and engaged by the engaging

bolts

82a and 82b on both sides and the urging force of the pressing spring 81. At this time, the frictional resistance obtained by the surface sliding can be adjusted by adjusting the urging force of the pressing spring 80, and therefore the lens holding force and the movability of the lens movement can be optimized.

Fig. 10 is a diagram showing a horizontal drive mechanism (power transmission in the X-axis direction), and fig. 11 is a diagram showing a vertical drive mechanism (power transmission in the Y-axis direction). Fig. 10 is a view seen from the rear side of the lens moving mechanism 32, and fig. 11 is a view seen from the front side of the lens moving mechanism 32.

In the horizontal driving mechanism of fig. 10, the rotational force of the X-axis actuator 61 attached to the fixed base 50 is transmitted from the worm 65 to the driving unit 67 while being reduced in speed by the gear train 66 (worm wheels 66a to 66 c). The drive unit 67 is constituted by a lead screw 671 and a drive nut 672, and transmits a rotational force from the gear train 66 to the lead screw 671 to advance the non-rotational drive nut 672 (hereinafter referred to as a lead screw nut) engaged therewith. The X base is coupled to the lead screw nut 672, and moves the X base 60 in the X axis direction.

Similarly, in the vertical drive mechanism of fig. 11, the rotational force of the Y-axis actuator 71 to which the X base 60 is attached is reduced in speed from the worm 73 via the gear train 74 (worm gears 74a to 74c) and transmitted to the drive unit 75. The drive unit 75 is constituted by a lead screw 751 and a drive nut 752, and transmits a rotational force from the gear train 74 to the lead screw 751 to drive the non-rotating drive nut 752 (hereinafter, referred to as a lead screw nut) engaged therewith. The Y base 70 is coupled to a lead screw nut 752, and the Y base 70 is moved in the Y axis direction.

In order to improve the assemblability, if the X-axis actuator 61, the worm 65, the gear train 66, and the driving unit 67 are assembled in advance as a unit, the horizontal driving mechanism can be completed only by disposing the unit on the fixed base 50. The same is true for the vertical drive mechanism.

Fig. 12 is a view showing an internal structure of the horizontal driving screw, and fig. 13 is a view showing an internal structure of the vertical driving screw. In both figures, (a) shows an assembled state and (b) shows an exploded state. In the horizontal drive, the worm gear 66c and the coaxial lead screw 671 are rotated, and the thus engaged lead screw nut 672 advances the X base 60. In the vertical driving, the worm wheel 74c and the coaxial lead screw 751 are rotated, and the thus-engaged lead screw nut 752 advances the Y base 70.

Inside the horizontally driven screw nut of fig. 12, an auxiliary screw nut 672b (hereinafter, referred to as an auxiliary nut) other than the screw nut 672 is disposed so as to face the screw nut 672, and a wave washer 672c as an elastic member is interposed therebetween. As the auxiliary nut 672b, for example, a polygonal nut of 12-angle shape is used. By providing the double nut structure, the backlash when the screw 671 drives the screw nut 672 is reduced, and the clearance between the screw 671 and the screw nut 672 and the frictional force can be adjusted by the pressure from the wave washer 672c, so that the amount of backlash can be adjusted.

Similarly, in the interior of the vertical drive screw nut of fig. 13, an auxiliary nut 752b is disposed to face the screw nut 752, and a wave washer 752c as an elastic member is interposed therebetween, thereby forming a double nut structure. By providing the double nut structure, backlash when the screw 751 drives the screw nut 752 is reduced, and the amount of backlash can be adjusted by adjusting the clearance and the frictional force between the screw 751 and the screw nut 752 by the pressure from the wave washer.

The assembly of the

lead screw nuts

672, 752 in fig. 12 and 13 will be explained. The auxiliary nuts 672b, 752b are fixed to the

lead nuts

672, 752 using, for example, コ -shaped

nut fixing members

672a, 752a and fixing nuts 672b, 752 d. The width of the

nut fixing pieces

672a, 752a is equal to the diameter of the auxiliary nuts 672b, 752 b.

In the horizontal drive screw nut of fig. 12, bolt holes are formed in 2 places, for example, on the axial surface of the auxiliary nut 672b, and holes are formed in 6 places, for example, on the surface facing the nut fixing member 672a at an equal angle. Further, holes are opened at 1 place in each of both side surfaces of the screw nut 672, and holes are opened at 1 place in the opposing surface of the nut fixing member 672 a. Then, after the screw nut 672 and the auxiliary nut 672b are pressed by the wave washer 672c to adjust the interval, the auxiliary nut 672b is fixed to the nut fixing member 672a by the axial fixing bolt 672d, and the nut fixing member 672a is fixed to the screw nut 672 by the side fixing bolt 672 d. In this example, the fixing is performed by 3 fixing bolts. As a result, the distance between the screw nut 672 and the auxiliary nut 672b is fixed, and the rotation of the auxiliary nut 672b with respect to the screw nut 672 is locked to be in a non-rotating state.

Further, by increasing or decreasing the number of holes opened in the axial surface of the nut fixing member 672a, the width of the gap between the auxiliary nut 672b and the screw nut 672 can be changed. The gap between the assist nut 672b and the lead screw nut 672 is adjusted by the torque of the lead screw 671, and the backlash amount and the friction force are optimized. After adjustment, the screw nut 672, the auxiliary nut 672a, and the wave washer 672c are fixed by the nut fixing member 672a to form a drive unit 67, thereby improving assemblability.

The assembly of the vertical drive screw nut of fig. 13 is also the same, and the description thereof is omitted.

Fig. 14 is an explanatory view of the double nut structure for reducing backlash. The lead screw 104 is attached to 2 lead screw nuts 101 and 102 via elastic members such as wave washers and springs. When the screw nut 102 for assisting rotation is brought close to the screw nut 101 side, the elastic member 103 is compressed to apply a pressure in the axial direction, so that 2 screw nuts 101 and 102 are separated from each other. As a result, the inclined surfaces of the threads of the screw nuts 101 and 102 are in a state of pressing the inclined surfaces of the threads of the screw 104, and the pressed inclined surfaces of the screw nut 101 and the screw nut 102 are opposite to each other. Therefore, even when the screw 104 is reversed to reverse the moving direction, backlash can be reduced by keeping the thread of the screw 104 in constant contact with the thread of the screw nuts 101 and 102. Further, by changing the interval between the 2 screw nuts 101 and 102, the thrust (pressure) of the elastic member 103 is adjusted, and the backlash amount and the frictional force can be optimally set.

Hereinafter, a modification of the double nut structure will be described.

Fig. 15 is a diagram showing another configuration example of the double nut structure. To the 2 screw nuts 101 and 102 attached to the screw 104, a pressure is applied in the axial direction so as to be close to each other by the 2 elastic members 103a and 103b provided on the outer side. The 2 elastic members 103a, 103b are fixed to the fixing member 105 from the outside thereof. At this time, the thread of the screw nut 101, 102 is pressed against the thread of the screw 104, and the pressing slopes of the screw nut 101 and the screw nut 102 are opposite to each other. Therefore, backlash can be reduced when the moving direction is reversed. The other elastic member may be configured to omit the elastic member 103a and directly fix the screw nut 101 to the fixing member 105, for example.

Fig. 16 is a diagram showing a specific shape of the auxiliary nut. (a) An example of a 12-angle nut 110 as a polygonal nut is shown. The fixing

threads

672d and 752d shown in fig. 12 and 13 pass through the threaded hole 111. At this time, the outer circumference 12 of the 12-degree screw 110 can be fixed to the holding surface of the fixture 105, and thus can be positioned at 12 positions of one rotation.

(b) The gear-shaped nut 112 is an example of a fine concave-convex processing (embossing processing) performed on the outer periphery. At this time, since the concavo-convex processing portion can be deformed, an arbitrary position of the outer periphery can be fixed by the holding surface of the fixing member 105. In addition, since a sufficiently large holding force of the gear-shaped nut 112 by the fixing member 105 can be obtained at this time, the bolt hole 111 for fixing the bolt in (a) can be omitted.

As described above, in embodiment 1, the double nut structure is adopted for the horizontal driving screw nut 672 and the vertical driving screw nut 752 in the lens moving mechanism 32, so that backlash generated when the moving direction of the lens is reversed can be reduced, and delay in the lens moving operation can be eliminated.

Example 2

In embodiment 2, a lens moving mechanism capable of easily correcting the inclination of the optical axis of the projection lens will be described. As shown in fig. 6, initial correction of the inclination caused by the position of the projection lens 31 and the self weight of the lens can be performed by adjusting the insertion amount of the 4 lens position correction bolts 411a to 411 d. However, when the projection lens 31 is replaced with a heavy lens, the optical axis needs to be further corrected by the own weight of the lens. In the method of adjusting the 4 correction bolts 411a to 411d, the adjustment work becomes complicated. Therefore, the mechanism for simply correcting the tilt of the optical axis described below is supplemented.

Fig. 17 is a sectional view showing an optical axis correction mechanism of the projection lens. In the present embodiment, the inclination of the lens moving mechanism 32 when the heavy lens is mounted is corrected. When the lens moving mechanism 32 is mounted on the common base 4, it is attached to the common base 4 via an optical axis adjustment guide 90 provided at a lower portion of the lens moving mechanism 32. That is, a recess is provided near the tip of the bolt portion of the optical axis adjustment guide 90, and a fixing bolt 91 inserted from the lower portion of the common base 4 is engaged with the recess. Then, only by adjusting the insertion amount of the optical axis adjustment guide 90, the lens moving mechanism 32 can be tilted by engaging the concave portion of the optical axis adjustment guide 90 with the fixing bolt 91 to perform optical axis correction.

Fig. 18 is a diagram illustrating an example of optical axis correction of the projection lens. (a) The following states are represented: the lens moving mechanism 32 is tilted forward by the weight of the projection lens 31, and the optical axis is tilted downward from the horizontal direction. (b) Showing the state after the optical axis correction. In this correction, by pressing the optical axis adjustment guide 90 to the fixed wall 41 side, the lower portion of the lens moving mechanism 32 can be separated from the fixed wall 41, and the optical axis can be returned to the horizontal direction.

As in embodiment 2 described above, correction of the optical axis inclination can be easily performed only by pressing or returning the optical axis adjustment guide 90.

According to the embodiments described above, backlash in the lens moving mechanism is reduced, and correction of the inclination of the optical axis at the time of replacement of the projection lens becomes easy, enabling improvement of the operability for the user.

Description of the reference numerals

1 … casing

2 … optical engine

3 … projection optical system

4 … common base

5 … Screen

10 … projection type video display device

31 … projection lens

32 … lens moving mechanism

41 … fixed wall

42. 43 … pedestal part

50 … fixed base

60 … X-axis movable base

61 … X-axis actuator

65. 73 … Worm (work gear)

66. 75 … gear set

66 a-66 c, 74 a-74 c … wormwheel

67. 75 … drive unit

70 … Y-axis movable base

71 … Y-axis actuator

80 … pressing spring

81 … axle

82a … mating bolt

90 … optical axis adjustment guide

91 … fixing bolt

101 … lead screw nut

102. 110, 112 … auxiliary lead screw nut

103 … elastic member

105 … fixing piece

311 … lens barrel

312 … flange

411a to 411d … lens position correcting bolt

412 a-412 d … spring

413 … mounting bolt

671. 751 … lead screw

672. 752 … lead screw nut

672a, 752a … nut fixing piece

672b and 752b … auxiliary lead screw nut

672c, 752c … spring (wave washer)

672d and 752d ….

Claims

1. A projection type image display device for projecting an image from a projection lens, comprising:

a lens moving mechanism for holding the projection lens and moving the projection lens in 2 axial directions orthogonal to the optical axis of the projection light,

the lens moving mechanism includes: a horizontally movable base that moves the projection lens in a horizontal direction and a vertically movable base that moves the projection lens in a vertical direction; and a horizontal driving actuator for driving the horizontally movable base and a vertical driving actuator for driving the vertically movable base,

the driving force from the horizontal driving actuator and the vertical driving actuator is transmitted via a lead screw and 2 lead screw nuts engaged therewith, respectively, to move the horizontally movable base and the vertically movable base,

applying pressure to the 2 lead screw nuts by an elastic member so that the 2 lead screw nuts are moved away from or close to each other in an axial direction of the lead screw,

the lens moving mechanism is inserted with 4 lens position correcting bolts from the back side, and is inserted with 4 mounting bolts from the front side, and is matched with a common base for holding the lens moving mechanism through a spring,

further, an optical axis adjusting guide is inserted into the common base from one side of the lens moving mechanism at a lower portion of the lens moving mechanism,

the optical axis adjustment guide has a recess near a tip of a bolt portion, a fixing bolt inserted from the common base side is engaged with the recess,

correcting an optical axis inclination of the projection lens held by the lens moving mechanism by adjusting an insertion amount of the optical axis adjustment guide,

the elastic member uses a wave washer.